氧气（O2）：氧气是从空气液化过程中提取的，空气中的氧气含量是21%，它是所有呼吸及燃烧过程的基础，因此是几乎所有生命过程的先决条件。氧气检测仪用于监测环境中氧气的含量，确保氧气浓度在安全范围内，避免过低或过高的氧气浓度对人体造成危害。

However, according to the Canadian Energy Centre, that cherished goal cannot be realized. This is true of fueling transport, ...

NCERT Solutions For Class 10 Chapter Carbon And Its Compounds: Well, NCERT books are considered to be the best resource for ...

13. Which of the following hydrocarbons undergo addition reactions: C2H6, C3H8, C3H6, C2H2 and CH4? Solution: Unsaturated hydrocarbons undergo additional reactions. C3H6 and C2H2 are unsaturated ...